avahi: add missing dependency on host-gettext

Fixes:
http://autobuild.buildroot.org/results/1dd5993d2ead9a92e2eb73227b19697728950b86/build-end.log.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/avahi/avahi.mk

@@ -85,7 +85,8 @@ AVAHI_CONF_OPT = --localstatedir=/var \
 		--with-autoipd-user=default \
 		--with-autoipd-group=default
 
-AVAHI_DEPENDENCIES = $(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext) host-intltool host-pkgconf
+AVAHI_DEPENDENCIES = $(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext) host-intltool \
+       host-pkgconf host-gettext
 
 ifneq ($(BR2_PACKAGE_AVAHI_DAEMON)$(BR2_PACKAGE_AVAHI_AUTOIPD),)
 AVAHI_DEPENDENCIES += libdaemon